Asset tracking systems are often designed to monitor whether an asset is within a prescribed geo-spatial area, which is often referred to as being defined by a geofence. Asset tracking systems may employ tracking devices that are applied to tracked assets and transmit an alarm message including the assets' locations when they leave the geofence. As an example, the asset may be a pet or a piece of construction equipment, and the geofence may encompass the pet's yard or the equipment's construction site.
In a type of asset tracking systems, the devices may monitor wireless beacon signal with a signal strength configured such that the signal will be received within a signal strength threshold encompassing the geofence. The beacon signal defines a “safe zone” such that so long as the tracking device can receive the beacon signal is received within the threshold the tracker device is within the geofence, and therefore can remain in a low-power mode. Tracking devices of this design may remain in a power-savings mode so long as they stay within the base safe-zone.
When a tracking device leaves the safe-zone defined by the beacon signals, which may be referred to as a “breach” of the geofence, the tracking device no longer receives the short-range wireless transmissions of the beacon within the predefined threshold strength, which cause the tracking device to enter a high power mode for obtaining a location (e.g., a GPS fix) and transmitting alarm messages via a high-power transceiver (e.g., cellular transceiver). For example, the tracking device on a dog may transmit an alarm message as a SMS message to the dog owner. However, if the asset and corresponding tracking device is removed from the safe-zone by the owner (e.g., the dog goes on a walk with the owner), the tracking device may transmit false alarm messages and unnecessarily consumer significant amounts of battery power by activating the high-power transceiver.